Large quantities of coal are burned world wide. Typically, coal is ground to a fine powder, conveyed to the boiler and burned to produce steam to power turbines which generate electricity. A by-product of this coal combustion is a fly ash residue. During the combustion process inert clay and shale minerals in the fly ash react with lime to form cementacious materials. This pozzolanic property of fly ash is exploited. That is, fly ash incorporated into cement reacts with free lime during the concrete forming process to produce a cement forming a stronger concrete. Using fly ash as a pozzolan in concrete saves on the amount of cement to be used. There is a caveat however to using fly ash in concrete. The American Society for Testing and Material specifies a carbon content in fly ash of less than 6% as being useable in cement. It would be advantageous to employ fly ash having higher concentrations of carbon as a fly ash additive in cement to make concrete. The herein disclosed invention addresses this problem and offers a solution.
It is known in the art to treat fly ash containing higher levels of carbon with ozone to make the fly ash with a higher level carbon useable in cement. This ozone treatment of fly ash is referred to in the art as pacification. When pacifying fly ash, the prior art has employed an ozone generated by an external source. The elimination of this prior art external ozone generation system is a main goal of the present invention. As described, reacting ozone with high carbon fly ash produced by the combustion of fossil fuels will pacify the carbon and make it possible to use high carbon fly ash as a concrete additive.
The herein disclosed invention recognizes that processes designed to reduce carbon in fly ash are often remiss in not effectively reducing the carbon content to acceptable levels. The herein disclosed invention is designed to remedy the problem of insufficient or inefficient carbon reduction of fly ash. An example of a process in which carbon in fly ash may not be sufficiently reduced is in a triboelectric process for reducing carbon in fly ash.